JPS62296635A - Data transmission system - Google Patents

Abstract

PURPOSE:To decrease the restoration recovery time by generating a specific data corresponding to the interruption of a clock signal from a sending station by a relay station and sending the data to a reception station so as to discriminate it properly as to whether the interruption of the clock signal resides in the relay station or the sending station. CONSTITUTION:The encoder 20 of the relay station uses a shaped clock signal from a shaping circuit 17 to encode a data signal and sends the result to the reception station via a driver 21. On the other hand, if the clock signal 109 is interrupted, a clock signal interruption detecting circuit 16 sends a clock interruption detecting signal to a multiplexer 19. The multiplexer 19 selects a specific data inputted from a specific data generating circuit 18 in place of a data signal sent from the decoder 15 and sends the result to the reception station via the encoder 20 and the driver 21. Thus, the reception station discriminates it accurately as to whether the interruption of clock signal exists in the transmission station or the relay station.

Description

[Detailed Description of the Invention] Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a data transmission system, and in particular, to a method for notifying a corresponding receiving station of a clock signal disconnection from a transmitting station detected at a relay station. The present invention relates to a data transmission method configured to.

rPrior Art] Conventionally, in this type of data transmission system, a relay station is provided between a transmitting station and a receiving station corresponding to a transmission span, and a data signal from the transmitting station is transmitted to the relay station. The signal is relayed by the receiver and transmitted to the receiving station.

[Problem that the invention seeks to solve]

In the conventional data transmission system described above, even if a clock signal interruption occurs due to a failure at the transmitting station, it is of course impossible for the receiving station to detect the clock signal interruption and identify the failure at the transmitting station. Moreover, there is a drawback that it is not possible to identify whether the failure of the clock signal interruption occurred at the transmitting station or at the relay station.

(Means for Solving the Problems) The data transmission system of the present invention provides a data transmission system formed by a transmitting station, a receiving station, and a relay station, in which the relay station receives data from the transmitting station. means for detecting a clock signal disconnection in data; and means for transmitting specific data to the receiving station in response to the clock signal disconnection; The apparatus includes means for detecting signal interruption and means for detecting reception of the specific data.

[Example 1 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a system block diagram of an embodiment of a data transmission system according to the present invention, and FIGS. 2, 3, and 4 show the main parts of a transmitting station, a receiving station, and a relay station, respectively, in this embodiment. In FIG. 6, which is a block diagram shown in FIG.
From relay station 2 to relay station 2, data signal 101 and clock signal 102 are transmitted separately in parallel form, but from relay station 2 to receiving station 3, both signals are combined and transmitted in series form. (data signal + clock signal) 103. As shown in FIG. 2, in the transmitting station 1, parallel transmission data 104 including a data signal and a clock signal is converted into serial transmission data 105 in a parallel-to-serial conversion circuit 4, and is input to an encoder 5. In the encoder 5, the serial transmission data 105 is encoded, divided into a data signal 106 and a clock signal 1.07, output, and transmitted to the relay station 2 via the dry halo and 7, respectively.

In the relay station 2 shown in FIG. 4, a data signal 108 and a clock signal 100, which are separated from the transmitting station 1 and sent in parallel, are input to receivers 13 and 14, respectively, and their receiver outputs are , the data signal is sent to the decoder 15, and the clock signal is sent to the decoder] 5 Kuro...P/Municipal PIi1j! It is input to an output circuit 16 and a shaping circuit 17. Under normal conditions, decoder 1
At 5, the data signal is decoded and input to an encoder 20 via a multiplexer 19. In the encoder 20, the data signal is encoded using the shaped clock signal sent from the shaping circuit 17, and sent to the receiving station 3 along with the clock signal via the driver 21.
When the clock signal 109 sent to is "OFF", the clock signal disconnection detection circuit 16 detects "clock signal disconnection -1", and the clock disconnection detection signal is sent to the multiplexer 19. In the multiplexer 19, In response to the input of the clock interruption detection signal, the decoder 15
Instead of the data signal sent from the specific data generating circuit 18, specific data input from the specific data generating circuit 18 is selected and sent to the receiving station 3 via the encoder 20 and driver 21.

In the receiving station 3 shown in FIG.
and a clock signal 109, and the serial/parallel conversion circuit 1
Sent to 1. In the serial-to-parallel conversion circuit 11, the data signal 108 and the clock signal 109 are converted into parallel received data, and outputted through a predetermined processing operation.

However, relay station 2 sends data +4 to receiving station 3!
If the clock signal is interrupted during the transmission process, it becomes impossible to extract the clock signal that should have been sent from the relay station 2, and the decoder 9 In the clock signal disconnection detection circuit 1?1iIO provided at

In addition, in the case of "clock signal disconnection" during the process of transmitting data from the transmitting station 1 to the relay station 2, the specific data detection circuit 12 provided in conjunction with the serial/parallel conversion circuit 11 detects the specific data generation circuit 18
The specific data output from the clock signal is detected, and the clock signal interruption is recognized. In other words, in the case of a "clock signal disconnection", the receiving station 3 knows that the cause is the transmitting station 1.
It is possible to accurately identify whether it is located at the relay station 2 or at the relay station 2. [Effects of the Invention] As explained above, the present invention provides specific data generation means in a relay station for generating specific data and transmitting it to a receiving station in response to a clock signal disconnection at a transmitting station. This has the effect that the receiving station can accurately identify whether the C61 clock signal interruption is caused by the transmitting station or the relay station. This identification state is expected to facilitate identification of the cause of the failure in the event of a failure due to clock signal interruption, and is also expected to shorten recovery time.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of an embodiment of a data transmission system according to the present invention, and FIGS. 2, 3, and 4 are block diagrams showing main parts of a transmitting station, a receiving station, and a relay station, respectively. be. In the figure, 1... transmitting station, 2... relay station, 3... receiving station, 4... parallel to serial conversion circuit, 5.20... ...Encoder, 6.7.2
1... Driver, 8.13.14...
Receiver, 9.15... Decoder, 10.16
...Clock signal disconnection detection circuit, 11...
・Serial-to-parallel conversion circuit, 12...Specific data detection circuit, line 1 diagram line 2 field

Claims (1)

[Claims] In a data transmission system formed by a transmitting station, a receiving station, and a relay station, the relay station includes means for detecting clock signal interruption in data received from the transmitting station;
means for transmitting specific data to the receiving station in response to the clock signal disconnection; the receiving station includes means for detecting a clock signal disconnection in data received from the relay station; means for detecting reception of the
A data transmission method characterized by comprising: